Marfan syndrome is a hereditary connective tissue disorder. Many individuals with this condition die because of the associated heart and blood vessel abnormalities. This study will compare the effectiveness of two medications, losartan and atenolol, at slowing aortic root enlargement in individuals with Marfan syndrome.

Annual Rate of Change in Aortic Root (Sinuses of Valsalva) Body-surface-area-adjusted Z-score [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

The rate of aortic root enlargement, expressed as the annual change in the maximum aortic-root-diameter z score indexed to body-surface area over a 3-year period following randomization

Secondary Outcome Measures:

Annual Rate of Change in Aortic Root (Sinuses of Valsalva) Absolute Dimension [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

The rate of change in the absolute dimension of the aortic root over a 3-year period following randomization

Annual Rate of Change in Ascending-aorta-diameter Z Score, Adjusted by Body-surface-area. [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in the Absolute Diameter of the Ascending Aorta [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Aortic-annulus-diameter Z Score, Adjusted by Body-surface Area [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in the Absolute Diameter of the Aortic Annulus [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Total Aortic Proximal Regurgitant Jet Area Indexed to Body-surface-area [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Weight [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Weight-for-age Z-score [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Weight-for-height Z-score [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Height [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Height-for-age Z-score [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Body Mass Index [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Body Mass Index for Age Z-score [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Arm Span to Height Ratio [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Annual Rate of Change in Upper to Lower Segment Ratio [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: No ]

Number of Participants With Aortic Dissection. [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: Yes ]

Event Rate of Aortic Dissection. [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: Yes ]

Percentage of participants who had aortic dissection over a 3-year period following randomization.

Number of Participants With Aortic-root Surgery. [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: Yes ]

Event Rate of Aortic-Root Surgery [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: Yes ]

Percentage of participants who had aortic-root surgery over a 3-year period following randomization.

Number of Death. [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: Yes ]

Event Rate of Death [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: Yes ]

Percentage of participants who died over a 3-year period following randomization.

Number of Participants With the Composite Adverse Clinical Outcomes, Including Aortic Dissection, Aortic-root Surgery and Death. [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: Yes ]

Event Rate of the Composite Adverse Clinical Outcomes, Including Aortic Dissection, Aortic-root Surgery and Death. [ Time Frame: Up to 3 years following randomization. ] [ Designated as safety issue: Yes ]

Percentage of participants who had aortic dissection, aortic-root surgery or death over a 3-year period following randomization

Participants with Marfan's syndrome and ≥3 maximum aortic root z-score received 0.5 - 4.0 mg/kg/day Atenolol (not to exceed a total dose of 250 mg), with a goal of a 20% or greater decrease in the mean heart rate.

Marfan syndrome is an inheritable disorder that affects the body's connective tissue. An abnormal protein results in connective tissue that is weaker than normal. Because connective tissue is found throughout the body, Marfan syndrome can affect many body systems, including the skeleton, eyes, nervous system, skin, lungs, heart, and blood vessels. Overall, heart and blood vessel abnormalities are the leading cause of death in individuals with Marfan syndrome. A common blood vessel abnormality associated with this disease involves the aorta, which is the large artery that carries blood away from the heart to the rest of the body. The aortic root, the portion of the aorta that is attached to the heart, may enlarge and tear or even rupture. A tear or rupture is considered a life-threatening emergency. Recent studies have shown that the medication losartan may reduce aortic root growth and improve heart function. The purpose of this study is to compare the effectiveness of losartan versus atenolol at slowing aortic root growth in individuals with Marfan syndrome.

This 3-year study will enroll individuals with Marfan syndrome. Participants will be randomly assigned to receive either losartan or atenolol on a daily basis. All participants will initially receive a low dose of their assigned medication. This dose will be gradually increased every 3 to 4 weeks until the maximum tolerated dose is reached. A continuous electrocardiogram (ECG) that monitors heart rate and activity in 24-hour intervals will be used to determine the proper dose increase for each participant. Participants will then receive the maximum tolerated dose for the remainder of the study. Study visits will occur at baseline and Months 6, 12, 24, and 36. Each study visit will include a physical examination, a medical history review, an ECG, an echocardiogram, and questionnaires. Additionally, at the baseline study visit blood will be collected for laboratory testing.

Eligibility

Ages Eligible for Study:

6 Months to 25 Years (Child, Adult)

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Diagnosis of Marfan syndrome, according to Ghent criteria (more information can be found in Appendix D of the protocol)

Aortic root Z-score greater than 3.0

Exclusion Criteria:

Prior aortic surgery

Aortic root dimension at the sinuses of Valsalva greater than 5 cm

Planned aortic surgery within 6 months of study entry

Aortic dissection

Shprintzen-Goldberg syndrome

Loeys-Dietz syndrome

Therapeutic (i.e., for arrhythmia, ventricular dysfunction, or valve regurgitation) rather than prophylactic use of angiotensin-converting enzyme (ACE) inhibitor, beta-blocker, or calcium channel blocker

History of angioedema while taking an ACE inhibitor or beta-blocker

Intolerance to losartan or other angiotensin II receptor blocker (ARB) that resulted in termination of therapy

Intolerance to atenolol or other beta-blocker that resulted in termination of therapy

Chronic use of steroids and/or beta-adrenergic agents with exacerbations of asthma that are frequent (averaging three or more per year) or severe (requiring hospitalization)

Diabetes mellitus

Pregnant or planning to become pregnant within 36 months of study entry

Inability to complete study procedures, including history of poor acoustic windows (i.e., inability to obtain accurate measurement of aortic root)

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00429364